One of the most successful digitisation projects in Britain is Cambridge University’s The Complete Works of Charles Darwin. It has recently added private papers, including the first draft of his theory of evolution, notes from the voyage of the Beagle and recipe book by Emma Darwin.
The project has has fantastic media exposure in the UK and beyond, including a mention on prime time television. As the history page of the resource recounts, this is not without its problems.
A related project at Camrbridge is the Darwin Correspondence Project, which presents letters Darwin sent and received. There is an interesting research project in waiting to try and bring the two resources together